Autotitrator based on an Arduino Open Source Pump Castillo Santaella, Teresa del Maldonado Valderrama, Julia Fernández Rodríguez, Miguel Ángel Arduino Automated titration PH meter Acid–base titration is a quantitative analysis that enables knowing the quantity of acidic or basic groups present in a solution sample. It consists in the addition of base or acid to the solution sample while monitoring the pH to reach a neutral pH. The titration can be automated and here we present a low cost Arduino based Open Source Pump (OSPump) modified to act as an automated titrator with an obsolete but reliable Metrohm 713 pH meter. Our device is 50 times less expensive than second hand units from the pH meter manufacturer and inherently open to customization. We present two validation cases of study, including the lipolysis of a vegetable olive oil in water emulsion, characterized by the OSPump Titrator. 2023-10-24T10:47:22Z 2023-10-24T10:47:22Z 2023-08-07 info:eu-repo/semantics/article T. del Castillo-Santaella et al. Autotitrator based on an Arduino Open Source Pump. HardwareX 15 (2023) e00464[https://doi.org/10.1016/j.ohx.2023.e00464] https://hdl.handle.net/10481/85215 10.1016/j.ohx.2023.e00464 eng http://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess Atribución 4.0 Internacional Elsevier